Dear all,

There are two problems that I have written a code for:

1. Program to determine whether a number is a factorial number or not.

A. I am getting the errors: (a) Linker error - undefined reference to 'WinMain@16' (b) Id return 1 exit status (c) Build Error. My code for this problem is:

Code:#include<stdio.h> int main() { int i,n,prod=1; printf("Enter n to be checked"); scanf("%d",&n); if(n==1 || n==2) { printf("n is a factorial number"); } else if(n>2) { for(i=1;i<=n/2;) { while (prod<=n) { prod*=i; i++; } } } if(prod==n) { printf("factorial"); } else printf("not factorial"); system("pause"); return(0); }

2. Program to calculate all the coefficients of x for a given value of n. Here nCr in the rth power of x in the expansion of (x+1)^n is given by

nCr = n! / r! (n-r)!

A. I am getting the errors: (a) Linker error - undefined reference to 'WinMain@16' (b) Id return 1 exit status (c) Build Error. My code for this problem is:

Code:#include<stdio.h> int main() { int n,r,i,num,*coefficients,*den1,*den2; printf("enter the value of n"); scanf("the values are %d",&n); //for calculating r! for(r=0;r<=n;r++) { if(r==0) { den1[r]=1; } else for(i=1;i<=r;i++) { den1[r]*=i; } } //for calculating n-r! for(r=0;r<=n-r;r++) { if(r==0) { den2[r]=1; } else for(i=0;i<=n-r;i++) { den2[r]*=i; } } //for calculating n! for(i=1;i<=n;i++) { num*=i; } //for calculating coefficients for(i=0;i<=n;i++) { coefficients[i]=(num/(den1[i]*den2[i])); printf("the %dth coefficient is %d\n",i,coefficients[i]); } system("pause"); return 0; }

3. Generating the numbers of the Lucas sequence which is a variation of fibonacci sequence. The lucas sequence is:

1 3 4 7 11 18 29 ...

A. This code for this is successfully compiled but on running the program it hangs after entering the value of integer 'n'. My code for this problem is:

Thank you for you help.Code:#include<stdio.h> int main() { int i,n,*a; printf("number of terms of the lucas sequence to be calculated"); scanf("%d",&n); for(i=3;i<=n;i++) { a[i-1]=3; a[i-2]=1; a[i]=a[i-1]+a[i-2]; printf("the lucas sequence to n terms is 1 3 %d",a[i]); } system("pause"); return